A firewall on a computer in the FRITZ!Box home network reports regular attacks ("Syn Flood", "Denial of Service (DoS)") on TCP port 80 and/or 14013.

Every five seconds, a firewall or an application for analyzing network connections such as Wireshark reports packets of type 0x88e1 (EtherType).

Connections do not pose a security threat

The incoming connections do not come from the internet. Instead, they come from the FRITZ!Box and do not pose a security threat.

TCP Port 80:The FRITZ!Box uses TCP port 80 to check regularly whether computers or other devices connected to the FRITZ!Box offer web services accessible over HTTP, such as a user interface. The web services of these devices can be accessed directly under "Home Network > Home Network Overview" in the FRITZ!Box user interface.

TCP port 14013:The FRITZ!Box uses TCP port 14013 to check regularly whether the FRITZ!Box Parental Control software is installed on the Windows computers in the home network. This software informs the FRITZ!Box which Windows user account is being used on the computers, allowing it to then restrict internet access for certain Windows users.

Type 0x88e1:The FRITZ!Box uses packets of EtherType 0x88e1 to check regularly whether there are any FRITZ!Powerline adapters in the home network. Any adapters it finds are displayed in the FRITZ!Box user interface under "Home Network > Home Network Overview".

Note:If you do not want to receive these messages, configure the device's firewall so that it allows incoming connections to TCP port 80 and 14013 or packets of type 0x88e1. Refer to the manufacturer of the firewall for information on how to set it up, for example consult the manual.